Systems and methods for using linked documents

ABSTRACT

Systems, methods, and non-transitory computer readable media are provided for using linked documents. A system may receive, from a computing device, a request for a document. Content of the document may be defined based on state information and stateless information. A system may determine a local replica of the document in a local database. The local replica of the document may be linked to a primary replica of the document. The local replica of the document may include a snapshot of the primary replica of the document. The primary replica of the document may be stored in a remote database which may be accessible through a remote server. The system may subscribe to the primary replica of the document through the remote server, and may provide access to the document to the computing device based at least in part on the subscription to the primary replica of the document.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/450,903, filed Jun. 24, 2019, which is a continuation of U.S. patentapplication Ser. No. 15/835,847, filed Dec. 8, 2017, now U.S. Pat. No.10,380,196, the contents of which is hereby incorporated by reference inits entirety into the present disclosure.

FIELD OF THE INVENTION

This disclosure relates to approaches for using linked documents.

BACKGROUND

Under conventional approaches, a document may be stored in a databaseand be accessible for viewing and/or editing. Content of a document maybe defined based on stateless information (e.g., stateless assets, suchas images, that do not change between versions of the document) and/orstate information (e.g., different operational transforms being appliedto one or more portions of different versions of the document).Restricting content of the document to stateless information may limitthe flexibility and versatility of the document. For example,restricting content of the document to images may require changes in theactual images used for the document (e.g., uploading different images)to change the content of the document. Using state information to definecontent of the document may provide for more flexible/versatile contentchanges. For example, operational transforms being applied to thedocument may be changed (e.g., adding, removing, and/or modifying one ormore operations) to change the content of the document.

However, using state information to define content of the document mayresult in mismatch between different copies of the document based on amismatch in state information. For example, changes in state informationmay not be propagated to different locations (e.g., databases, servers)at which copies of the document are stored, and the content of thedocument may be different based on the location from which the copy ofthe document is accessed. Providing clients in different locations withaccess to up-to-date state information for the documents may bedesirable for a number of reasons. For example, providing up-to-datestate information can enable a live view of the document (e.g., viewupdated version of document) and collaboration using the same version ofthe document by clients in different locations. Further, providingup-to-date state information can enable views of the same version of thedocument through different computing devices/at different times.

SUMMARY

Various embodiments of the present disclosure may include systems,methods, and non-transitory computer readable media configured toprovide for use of linked documents. Various embodiments of the presentdisclosure may include systems, methods, and non-transitory computerreadable media configured to receive, from a computing device, a requestfor a document. Content of the document may be defined based on stateinformation and stateless information. A computing system may determinea local replica of the document in a local database. The local replicaof the document may be linked to a primary replica of the document. Thelocal replica of the document may include a snapshot of the primaryreplica of the document. The primary replica of the document may bestored in a remote database which may be accessible through a remoteserver. The computing system may subscribe to the primary replica of thedocument through the remote server, and may provide access to thedocument to the computing device based at least in part on thesubscription to the primary replica of the document.

In some embodiments, the subscription to the primary replica of thedocument may include one or more updates to the snapshot of the primaryreplica of the document. The subscription to the primary replica of thedocument may include one or more updates to the state information forthe document. In some embodiments, the stateless information may belocally stored.

In some embodiments, providing access to the document to the computingdevice may include receiving one or more edits to the document from thecomputing device, and transmitting information describing the edit(s) tothe remote server. The remote server may have ultimate editorial controlover the primary replica of the document.

In some implementations, the computing device may be logged into thecomputing system using a given credential, and the computing system'saccess to the primary replica of the document through the remote servermay be validated using the given credential. The given credential may bevalidated based on trust relationships between an exchanger andauthentication processes.

These and other features of the systems, methods, and non-transitorycomputer readable media disclosed herein, as well as the methods ofoperation and functions of the related elements of structure and thecombination of parts and economies of manufacture, will become moreapparent upon consideration of the following description and theappended claims with reference to the accompanying drawings, all ofwhich form a part of this specification, wherein like reference numeralsdesignate corresponding parts in the various figures. It is to beexpressly understood, however, that the drawings are for purposes ofillustration and description only and are not intended as a definitionof the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain features of various embodiments of the present technology areset forth with particularity in the appended claims. A betterunderstanding of the features and advantages of the technology will beobtained by reference to the following detailed description that setsforth illustrative embodiments, in which the principles of the inventionare utilized, and the accompanying drawings of which:

FIG. 1 illustrates an example environment for using linked documents, inaccordance with various embodiments.

FIG. 2 illustrates an example diagram, in accordance with variousembodiments.

FIG. 3 illustrates another example diagram, in accordance with variousembodiments.

FIG. 4 illustrates yet another example diagram, in accordance withvarious embodiments.

FIG. 5 illustrates a further example diagram, in accordance with variousembodiments.

FIG. 6 illustrates a flowchart of an example method, in accordance withvarious embodiments.

FIG. 7 illustrates a block diagram of an example computer system inwhich any of the embodiments described herein may be implemented.

DETAILED DESCRIPTION

A claimed solution rooted in computer technology overcomes problemsspecifically arising in the realm of computer technology. In variousimplementations, a computing system may receive, from a computingdevice, a request for a document. Content of the document may be definedbased on state information and stateless information. For example, insome embodiments, content of the document may be determined using anoperational transform model that performs operations using stateinformation and stateless information. When processing the request, thecomputing system may find a local replica of the document in a localdatabase. In some embodiments, the local replica of the document may belinked to a primary replica of the document. For example, a field in thelocal replica of the document may identify or reference the primaryreplica of the document. In some embodiments, the local replica mayinclude a snapshot (serialized state) of the primary replica of thedocument. The primary replica of the document may be stored in a remotedatabase and may be accessible through a remote server. In someembodiments, the remote server may have ultimate editorial control overthe primary replica of the document.

The computing system may subscribe to the primary replica of thedocument through the remote server and may provide access to thedocument to the computing device from which the request was received,for example, based on the subscribed primary replica of the document.The computing system, which acts as a server to the computing device,may become a client of the remote server for purposes of accessing theprimary replica of the document.

In some embodiments, the subscription to the primary replica of thedocument may include one or more updates to the snapshot of the primaryreplica of the document. The computing system may update the snapshot ofthe primary replica of the document in the local replica of the documentwhile continuing to subscribe to the primary replica of the document.

In some embodiments, the subscription to the primary replica of thedocument may include one or more updates to the state information forthe document. The computing system may receive update(s) to the stateinformation (e.g., additional operations to be performed) for thedocument so that the computing system may provide an updated replica ofthe document to the computing device.

In some embodiments, the stateless information may be locally stored.For example, the document may include one or more layers defined bystateless assets and provision of the document to the computing devicemay include provision of locally stored stateless assets. Suchprovisioning of stateless information may reduce the costs (e.g.,network bandwidth, computer processing) required to provide the documentto the computing device.

In some embodiments, providing access to the document to the computingdevice may include receiving one or more edits to the document from thecomputing device and sending information describing the edit(s) to theremote server. For example, information describing the edit(s) to thedocument, as received from the computing device, may be cached by thecomputing system and sent to the remote server for potentialmodification of the primary replica of the document.

In some implementations, the computing device may be logged into thecomputing system using a given credential (e.g., token). In someembodiments, the computing system's access to the primary replica of thedocument through the remote server may be validated using the givencredential. The given credential may be validated based on trustrelationships between an exchanger and one or more authenticationprocesses. Such validation of the computing device may allow a user ofthe computing device to access the primary replica of the document bygoing through an authentication/authorization process corresponding tothe computing system and without going through a separateauthentication/authorization process corresponding to the remote server.

The approaches disclosed herein enable access to a given document (e.g.,data object) from multiple locations (e.g., geo-replicating a live viewof data objects) and allow for collaborative document usage (e.g.,collaborative document editing). Users/clients are able to access localreplicas of documents maintained by local servers, which become clientsof remote servers maintaining primary replicas of documents. Rather thansimply replicating static views of data objects (e.g., at periodicintervals), an operational transform framework provides for live viewsof documents. Such live views of documents may be provided inconjunction with periodic updates for documents.

In general, a document may refer to a collection of information. Forexample, a document may refer to a collection of visual information(e.g., text, image, video), audio information (e.g., sound recording,music), and/or other information. A document may be represented as oneor more electronic files. In some instances, information within adocument may be organized with other information or separately fromother information. For example, a document may include a marked-up (orannotated) map with different information (e.g., image information,marking information) stored within different layers that define themarked-up map (e.g., base map defined by stateless information, markingson the map defined by state information). While the disclosure isdescribed herein with respect to documents containing maps, this ismerely for illustrative purposes and is not meant to be limiting. Thetechniques described herein may be applied to other types of documents,other types of information defining content of documents, and otherorganizations. Many variations are possible.

FIG. 1 illustrates an example environment 100 for using linkeddocuments, in accordance with various embodiments. The exampleenvironment 100 may include a computing system 102. The computing system102 may include one or more processors and memory. The processor(s) maybe configured to perform various operations by interpretingmachine-readable instructions stored in the memory. The environment 100may also include one or more datastores that are accessible to thecomputing system 102 (e.g., via one or more network(s)). In someembodiments, the datastore(s) may include various databases, applicationfunctionalities, application/data packages, and/or other data that isavailable for download, installation, and/or execution.

In various embodiments, the computing system 102 may include a datastore112, a request engine 114, a local replica engine 116, a subscriptionengine 118, and an access engine 120. The datastore 112 may includestructured and/or unstructured sets of data that can bedivided/extracted for provisioning when needed by one or more componentsof the environment 100. The datastore 112 may include one or moredatabases (e.g., storing document information, such as stateinformation, stateless information, operation logs). The datastore 112may include different data analysis/processing modules that facilitatedifferent data analysis/processing tasks, and/or other information to beused in the environment 100. While the computing system 102 is shown inFIG. 1 as a single entity, this is merely for ease of reference and isnot meant to be limiting. One or more components/functionalities of thecomputing system 102 described herein may be implemented in a singlecomputing device or multiple computing devices.

In various embodiments, the request engine 114 is configured to receivefrom a computing device, a request for a document. For example, thecomputing system 102 may include a server and may receive a request fora document from a computing device 122 (e.g., desktop device, laptop,mobile device) over one or more networks 124 (e.g., the Internet). Insome embodiments, the computing device 122 (or a user operating thecomputing device 122) may have to be logged into the server (e.g.,authenticated, authorized) to request the document and/or for thecomputing system 102 to provide the computing device 122 with access tothe document.

In some embodiments, content of a document may be defined based on stateinformation, stateless information, and/or other information. Forexample, content of the document may be determined using an operationaltransform model that performs operations using state information andstateless information. However, other well-known models for definingcontent of the document may be utilized.

Stateless information may refer to information that corresponds tocontent for a document that does not change with time/between versionsof the document. For example, stateless information may include visualinformation (e.g., defining images, videos), audio information (e.g.,defining sound clips, music), and/or other information that does notchange with time/between versions of the document. Further, statelessinformation may include stateless assets for defining contents of adocument. In some embodiments, stateless information may be storedlocally. That is, stateless information may be stored locally with thedocument/replica of the document that uses the stateless information.For example, a document/replica of the document may be stored within anelectronic storage/database (e.g., such as within the datastore 112) ofthe computing system 102 and the stateless information may be storedwithin the same electric storage/database and/or other electronicstorage/database of the computing system 102.

State information may refer to information defining content for adocument that may change with time/between versions of the document.State information may include operations that may be performed on thedocument to define the content of the document and/or other informationthat may change with time/between versions of the document. Suchoperations may be performed with respect to an image defined bystateless information or over an image defined by stateless information,for example. State information may define one or more objects that arebeing edited in the document. For instance, referring to the example ofa document including a marked-up map, a base map within the document maybe defined by stateless information (e.g., satellite image(s) of one ormore locations) while markings on the map (e.g., annotations,directions/routes) may be defined by state information (e.g.,operational transforms performed on one or more portions/layers of thedocument). As another example, one or more operations on the documentmay include importing information from other document(s) (e.g.,importing annotations from one or more other documents/maps into thedocument/map(s) in the document).

In some embodiments, operations to be performed on the document may berecorded within one or more operation logs. Based on the operationlog(s), multiple computing devices may present the same view ofdocuments. An operation log may contain information to enable acomputing device (e.g., the computing system 102, the remote server 126)to perform (replay) operations on top of a snapshot (serialized state)of a document to arrive at a consistent state. Individual computingdevices (e.g., servers) may maintain their own operation logs for thedocument. For example, a document may include a map with markings on themap defined by an operation log (including one or more operationaltransforms). Multiple users in different locations (e.g., accessing thedocument through different servers/databases) may see and collaborate onthe same view of the map by replicating the operation log.

Updates to operation logs (maintained by different servers in differentlocations) may effectuate updates to state information. In someembodiments, operations to be performed on the document may becommutative, and the operations may be applied optimistically on thefront end. Such application of operations on the document may providefor a resilient document management system and assist users to avoidconflicts within different replicas of documents being accessed.

Multiple replicas of a document may be stored within differentlocations. A replica may refer to a copy of a document. For example,multiple replicas of a document may be stored within electronicstorage/databases of computing devices (e.g., servers) in differentlocations. Multiple replicas of the document may be used by users indifferent locations to access the same view of the map. For example,multiple replicas of the document may be used by users in differentlocations to access the same version of the map. Replicas of a documentmay identify or reference a single version of the document or multipleversions of the document. For example, a single replica of a documentmay be used to access different versions of the document or differentreplicas of a document may exist for different versions of the document.

Multiple replicas of the document may include a primary replica of thedocument and one or more local replicas of the document. The primaryreplica of the document may refer to the replica of the document that ismaintained by a computing device having ownership of the document (e.g.,the replica stored within a database of a local/remote server that hasultimate editorial control over the document). For example, thecomputing system 102 may maintain a primary replica of a given documentwithin the datastore 112 and changes to the primary replica of the givendocument may be recorded within an operation log (stored in thedatastore 112 and/or other electronic storage of the computing system102).

A local replica of the document may refer to a copy of the document thatis maintained by a computing device not having ownership of the document(e.g., the replica stored within a database of a local server that doesnot have ultimate editorial control over the document). For example, thecomputing system 102 may maintain a local replica of a particulardocument in the datastore 112 and changes to the local replica of theparticular document may be recorded within an operation log (stored inthe datastore 112 and/or other electronic storage of the computingsystem 102). The changes to the local replica of the particular documentmay not be confirmed (e.g., accepted into the primary replica of thedocument) until the changes are acknowledged by a computing device(e.g., a remote server) having ownership of the document. In someembodiments, changes to a local replica of a particular document mayresult in generation of a new version of the particular document.

The local replica of the document may be linked to the primary replicaof the document. One or more fields in the local replica of the documentmay identify or reference the primary replica of the document. Thefields may include information to identify/locate the primary replica ofthe document/the computing device maintaining the primary replica of thedocument. For example, the local replica of the particular document inthe datastore 112 may include field(s) that identify/may be used toidentify the document as originating from/owned by a remote server 126.The local replica of the particular document in the datastore 112 mayalso include field(s) that identify/may be used to identify theidentifier (e.g., document ID) of the primary replica of the document inthe database of the remote server 126.

In some situations, the primary replica of the document may be stored ina remote database which may be accessible through a remote server (e.g.,the remote server 126). For example, a user may login to a local server(e.g., the computing system 102) to open the local replica of thedocument (e.g., stored in the datastore 112). Based on the user'sopening of the local replica of the document, the local server maycommunicate with the remote server (e.g., the remote server 126) toretrieve information (e.g., updates to an operation log) from theprimary replica of the document to update the local replica of thedocument. Such linkage between the primary and local replicas of thedocument may provide for a dependency relationship between the primaryand local replicas of the documents, where the local replica of thedocument depends on the primary replica of the document to determinewhat content is ultimately included in the document.

In some embodiments, the local replica of the document may include asnapshot (serialized state) of the primary replica of the document,which may be used to provide a view of the document when access to theprimary replica of the document is not available (e.g., due to a networkpartition or other connectivity issues). For example, the local replicaof the particular document stored in the datastore 112 may include asnapshot of the primary replica of the document, which allows thecomputing system 102 to provide a view of the document when thecomputing system 102 cannot communicate with the remote server (e.g.,the remote server 126) maintaining the primary replica of the document.

The primary replica of the document may be maintained by a computingdevice having ultimate editorial control over the document. For example,a remote server may maintain the primary replica of a given document andmay have ultimate editorial control over the primary replica of thegiven document (e.g., via use of one or more global commit logsaccessible through a version control system). That is, the remote servermay determine what changes to the primary replica of the document willbe accepted and change the primary replica of the document. Thesechanges may be made directly to the primary replica of the document ormade to a local replica of the document, for example. Changes made tothe primary replica of the document by the remote server may bepropagated to computing devices maintaining local replicas of thedocument. In some embodiments, the ownership of the document may bechanged. For example, the ownership of a particular document may changefrom the remote server 126 to the computing system 102 or the ownershipof a given document may change from the computing system 102 to theremote server 126. Many variations are possible!

In some embodiments, a local replica of a document may be created basedon sharing of a document. For example, rather than sharing a staticversion of the document, a user may choose to allow remote access to thedocument (e.g., by the same user, by different user(s)) via linking. Insome embodiments, the document may be selected for remote access in itsentirety. In some embodiments, the remote access of the document may beallowed through a user interface (e.g., APIs, graphical user interface)that allows for selective sharing of the document. That is, the userinterface may allow a user to specify one or more portions of thedocument (e.g., sections of the document, different layers of thedocument) for which remote access is allowed and/or one or more otherportions of the document for which remote access is not allowed.

In various embodiments, the local replica engine 116 is configured todetermine (e.g., find, identify, locate) a local replica of the documentin a local database. For example, the computing system 102 may maintaina local replica of a particular document in a database (e.g., thedatastore 112), and, responsive to a request for the document from thecomputing device 122, the computing system 102 can determine the localreplica of the particular document in the database. The local replica ofthe particular document may be linked to a primary replica of thedocument. The local replica of the particular document may include asnapshot of the primary replica of the particular document. The primaryreplica of the particular document may be stored in a remote databasewhich may be accessible through the remote server 126. Many variationsare possible.

The computing system 102 may be configured to determine the primaryreplica of the particular document in a remote database. Based on thelinking between the local and primary replicas of the particulardocument (e.g., as indicated in one or more fields of the local replicaof the document), the computing system 102 may communicate with theremote server 126 and determine the primary replica of the particulardocument in the remote database. Such determination of the primaryreplica of a document may allow for finding a document using the localreplica of the document. That is, based on a request for a document fromthe computing device 122 (e.g., a specific document request, a searchrequest), the local replica engine 116 may find the local replica of thedocument in the local database, which may then be used to find theprimary replica of the document in the remote database.

In various embodiments, the subscription engine 118 is configured tosubscribe to the primary replica of the document through the remoteserver 126. The subscription to the primary replica of the document maybe used to provide access to the document to the computing device 122.In some embodiments, the subscription to the primary replica of thedocument may create a server-client (e.g., master-slave) relationshipbetween the remote server 126 and the computing system 102. In someembodiments, the subscription to the primary replica of the document maycreate a server-client (e.g., master-slave) relationship between theprimary replica of the document and the local replica of the document.That is, the computing system 102, which acts as a server for thecomputing device 122 requesting the document, may become a client of theremote server 126 for purposes of accessing the primary replica of thedocument. In some embodiments, the computing system 102 may subscribe tothe primary replica of the document using the same mechanism by which alocal user/client of the remote server 126 subscribes to the primaryreplica of the document.

In some embodiments, the subscription to the primary replica of thedocument may include one or more updates to the state information forthe document. That is, based on the subscription to the primary replicaof the document, the computing system 102 may receive changes to thestate information (e.g., as reflected in an operation log) for theprimary replica of the document. Such changes may be received from theremote server 126, for example. The computing system 102 may receiveupdate(s) to the state information (e.g., additionaloperations/transactions to be performed) for the document so that thecomputing system 102 may provide an updated replica of the document tothe computing device 122 requesting the document. The computing system102 may receive updates to the state information once the subscriptionis established and/or during the subscription. For example, theoperation log of the local replica of the document may be synchronizedto the operation log of the primary replica of the document uponsubscription. As another example, the operation log of the local replicaof the document may (continually/periodically) be updated during thesubscription so that changes to the primary replica of the document(e.g., changes made at the remote server 126, changes made by othersubscribers of the primary replica) are reflected in the operation logof the local replica of the document.

In some embodiments, the subscription to the primary replica of thedocument may include one or more updates to the snapshot of the primaryreplica of the document. The computing system 102 may update thesnapshot of the primary replica of the document in the local replica ofthe document while subscribing to the primary replica of the document.The computing system 102 may update the snapshot of the primary replicaof the document once the subscription is established and/or during thesubscription. For example, the snapshot of the primary replica of thedocument may be modified based on the state of the primary replica ofthe document upon subscription. As another example, the snapshot of theprimary replica of the document may (continually/periodically) beupdated during the subscription so that changes to the primary replicaof the document are reflected in the snapshot.

In some embodiments, changes to the snapshot of the primary replica ofthe document may include changes to stateless information. The primaryreplica of the document may be changed to include different/additionalstateless information, and such stateless information may be provided tothe computing system 102 for local storage. For example, the content ofthe document including a map may be changed to includedifferent/additional image(s) for the map. The computing system 102 mayreceive the different/additional image(s) for the map for storage inlocal storage (e.g., within the datastore 112).

Thus, in some embodiments, the subscription to the primary replica ofthe document may establish a master-slave relationship between theremote server 126 and the computing system 102 and/or between theprimary replica of the document and the local replica of the documentfor a state/stateless information replication framework.

In various embodiments, the access engine 120 is configured to provideaccess to the document to the computing device 122 based at least inpart on the subscription to the primary replica of the document. Theaccess engine 120 may provide the computing device 122 with access tothe document based on synchronization of the local replica of thedocument with the primary replica of the document. For example, aprimary replica of a particular document may be stored in a remotedatabase. In this example, based on the request from the computingdevice 122 request for the particular document, the computing system 102may subscribe to the primary replica of the document, for example,through the remote server 126. The computing system 102 may alsosynchronize the local replica of the document with the primary replicaof the document. The access to document may be provided to the computingdevice 122 by providing the computing device 122 with access to thesynchronized local replica of the document.

Such synchronization of the different replicas of the document mayeffectuate pulling data for document updates. In some embodiments,rather than data for document updates being periodically pushed to thecomputing system 102 by the remote server 126, the document updates maybe provided by the remote server 126 to the computing system 102 whenthe document is accessed through the computing system 102. Such updatesmay allow for remote access to the updated document whenever connectionexists between the computing system 102 and the remote server 126.

Such updates may also reduce the load on periodic updates. For example,the remote server 126 may be configured to provide the computing system102 with updates to the document at a periodic time interval (e.g.,every 24 hours). Based on an access of the document through thecomputing system 102 between scheduled updates, the local replica of thedocument (state information, stateless information) may be synchronizedto changes in the primary replica of the document. Because updates tothe local replica of the document occurred prior to the periodic update,there may be fewer (or no) changes to be updated when the period updatetime is scheduled to begin.

Such updates may enable reduction on frequency of updates. For example,rather than consuming resources (e.g., computing power, memory,bandwidth) to provide frequent updates to different servers to make surethe users of the different servers are using updated documents, the setinterval for periodic updates may be increased because an access of adocument from a remote location will cause the local replica of thedocument to be updated.

In some embodiments, access to the document may be provided to thecomputing device 122 by loading the document from the primary replica ofthe document. In some embodiments, rather than loading the local replicaof the document, the access engine 120 may, using the subscription tothe primary replica of the document, load the primary replica of thedocument for access by the computing device 122. In such a case, thesynchronization of the local replica of the document may occur inparallel/subsequent to providing a view of the document to the computingdevice 122.

In some embodiments, providing access to the document to the computingdevice 122 may include use of locally stored stateless information. Forexample, the document may include one or more layers defined bystateless assets and the provision of the document to the computingdevice 122 may include provision of locally stored (non-conflicting)stateless assets. Such provision of stateless information may reduce thecosts (e.g., network bandwidth, computer processing) required to providethe document to the computing device 122. For example, stateless assetsfor a document including a map may include one or more satellite images,which may be much larger than state information (operations/transactionson/using the image(s)). The computing system 102 may store these imageslocally (e.g., datastore 112). In some embodiments, rather thanobtaining images from the remote server 126, the computing system 102may use these locally stored images to provide a view of the map to thecomputing device 122 instead. Such provision of locally stored statelessinformation enables users/computing devices to receive latency benefitsof using local data and an architectural benefit of modifying the localreplica of the map (e.g., inserting a new image, modifying icons,inserting comments/routes).

In some embodiments, providing access to the document to the computingdevice 122 may include receiving one or more edits to the document fromthe computing device 122 and sending information describing the edit(s)to the remote server 126. The computing system 102 can receive edit(s)to the document from the computing device 122. Information describingedit(s) to the document (e.g., changes in map inserting a new image,modifying icons, inserting comments/routes) may be cached by thecomputing system 102 and sent to the remote server 126 for potentialmodification of the primary replica of the document. The remote server126 may have ultimate editorial control over the primary replica of thedocument and may decide which of the modifications received from thecomputing system 102 will be incorporated into the primary replica ofthe document.

The linking of documents described herein may enable collaboration of adocument by multiple users/computing devices from multiple locationsand/or access of a document by a user from multiple locations. Forexample, users located in different geographic areas may use differentservers to access the document. The servers may include local replicasof the document, and the users may access the updated version of thedocument based on the link between the local and primary replicas of thedocument. Changes made to the local replicas of the document may beprovided to the server with the primary replica of the document forincorporation in the primary replica of the document. As anotherexample, a primary replica of a document may exist in a given databaseaccessible through a given server and a local replica of the documentmay exist in a particular database accessible through a particularserver. The user may access the document when connected to the givenserver by directly accessing the primary replica of the document. Theuser may also access the document when connected to the particularserver by using the local replica of the document.

The linking of documents described herein may enable creation of dynamicdependencies between documents. For example, a first document mayinclude a map and a second document may include annotations for the map.Copying the annotations from the second document to first given documentmay allow for static merging of information between the documents. Thatis, while the first document may be modified to include annotationsexisting within the second document at a time, subsequent changes to theannotations (or other changes) in the second document may not bereflected in the first document.

In some embodiments, rather than statically copying information from onedocument into another document, the documents may be linked todynamically share information between the documents. The linking mayinclude a master-slave linking or a peer linking. A master-slave linkingmay include dynamically importing information from one document (amaster document) into another document (a slave document). That is,information is exchanged in one way such that modifications made to themaster document are imported into the slave document while modificationsmade to the slave document are not imported into the master document. Apeer linking may include dynamically importing information betweenmultiple documents (a first peer document, a second peer document,and/or other peer documents). That is, information is exchanged inmultiple ways such that modifications made to one peer document areimported to other peer document(s). Such dynamic sharing of informationmay allow use of information from multiple documents in a singledocument. For example, different documents may be layered on top of eachother, a particular document may be used as a reference document, and/ora particular document may be used as a dependency for a document beingused. Many variations are possible.

In some embodiments, the access engine 120 may provide informationrelating to the status of a subscription to the primary replica of thedocument. For example, if the subscription to the primary replica of thedocument is effective (e.g., a network connection exists between thecomputing system 102 and the remote server 126), the access engine 120may provide information indicating the user is connected to the remoteserver 126 and/or accessing an updated version of the document. Forexample, a banner may be displayed indicating the user is connected tothe remote server 126 and/or accessing an updated version of thedocument. For example, if the subscription to the primary replica of thedocument is broken (e.g., a network connection does exist not betweenthe computing system 102 and the remote server 126), the access engine120 may provide information that the user is not connected to the remoteserver 126 and/or is not accessing the updated version of the documentand/or is accessing a local replica of the document. For example, abanner may be displayed indicating the user is not connected to theremote server 126 and/or is not accessing the updated version of thedocument and/or is accessing a local replica of the document.

Because the computing system 102 has been synchronizing the local andprimary replicas of the document while the subscription was valid, theuser may continue to use the document based on the local replica of thedocument (e.g., offline mode). When the connection between the computingsystem 102 and the remote server 126 is reestablished, the changes madeby the user during the offline mode may be compared with the primaryreplica of the document for potential incorporation into the primaryreplica of the document.

In some embodiments, a user may elect to toggle between connectivity/noconnectivity with the primary replica of the document and/or the remoteserver 126. Such election may allow the user to use/make changes to thedocument which may not be reflected back to the primary replica of thedocument. For example, a user may use such a feature to disconnectconnectivity and make edits that will not be seen by other collaboratorsof the document until connectivity is restored.

The dynamic synchronization of the different replicas of a document mayincrease user trust pertaining to use of the document. For example, ifthe different replicas of a document are only updated at a certaininterval, a user of a local replica of the document may be uncertain asto whether the user is using an updated version of the document.Different servers may be updated at different times and a user may seedifferent versions of the document depending on which server was used toaccess the document. A user may be unsure if the user is using anoutdated version of the map. The dynamic synchronization of thedifferent replicas of the document may allow a user to know that theuser is using an updated version of the map. In some embodiments, analert may be provided when the document is stale or not up-to-date basedon information relating to a status of the subscription to the primaryreplica of the document.

In some implementations, providing access to the document to thecomputing device 122 may include restricting access based onpermissions. For example, one or more portions of the document may berestricted based on sensitivity, classification, and/or other factors,and remote access of the document through the computing system 102 maybe limited based on the access level of the user/computing device 122.

In some implementations, the computing device 122 may be logged into thecomputing system 102 using a given credential (e.g., token) and thiscredential may be used to validate access to the primary replica of thedocument by the computing system 102 and through the remote server 126.The given credential may be validated based on trust relationshipsbetween an exchanger and one or more authentication processes (e.g.,authentication servers). The exchanger may allow sharing ofauthentication/authorization between different authentication processes.Such validation of the computing device 122 may allow a user of thecomputing device 122 to access the primary replica of the document bygoing through an authentication/authorization process for the computingsystem 102 and without going through a separateauthentication/authorization process for the remote server 126.

Lacking such validation of the computing device 122 may require the userto go through authentication/authorization process multiple times. Forexample, the user may be required to be authenticated/authorized whenthe user logs into the computing system 102 and again whenauthenticated/authorized the computing system 102 communicates with theremote server 126. For example, the user may be required to providelogin information when the user connects to the computing system 102 andwhen the computing system 102 connects to the remote server 126 (e.g.,for subscription to the primary replica of the document). Requiringusers to repeatedly provide their login information may create afrustrating user experience.

In some embodiments, credentials for users/computing devices may bestored for reuse. For example, the computing system 102 and the remoteserver 126 may disconnect (e.g., due to network partition), and thecomputing system 102 may provide a view of a document requested by thecomputing device 122 using a local replica of the document. When theconnection between the computing system 102 and the remote server 126 isrestored, a stored credential may be used to restore the subscription ofthe computing system 102 to the primary replica of the document throughthe remote server 126. Such resiliency may allow for a user/computingdevice 122 to prevent being logged off when connection to the remoteserver 126 is disconnected.

FIG. 2 illustrates an example diagram 200, in accordance with variousembodiments. The example diagram 200 may include a server A 210, aclient A 220, a server B 250, and a client B 260. The server A 210, theclient A 220, the server B 250, and the client B 260 may include one ormore processors and memory. The processor(s) may be configured toperform various operations by interpreting machine-readable instructionsstored in the memory. The client A 220 and/or the client B 260 mayinclude a computing device (e.g., desktop device, laptop, mobiledevice). The client A 220 may communicate with the server A 210 (e.g.,the client A 220 is logged into the server A 210) and the client B 260may communicate with the server B 250 (e.g., the client B 260 is loggedinto the server B 250).

The server A 210 may include a datastore A 212. In some embodiments, theserver A 210 may be configured to implement some, or all, of thefunctionalities of the computing system 102 as described above. Thedatastore A 212 may include one or more databases (e.g., storingdocument information, such as state information, stateless information,operation logs). The datastore A 212 may include a primary replica of adocument A (e.g., a document replica A 214) and a local replica of adocument B (e.g., a document replica B′ 216). The document replica B′216 may be linked to the document replica B 256. The document replica B′216 may include one or more fields that identify or reference thedocument replica B 256. The document replica B′ 216 may include asnapshot of the document replica B 256.

The server B 250 may include a datastore B 252. In some embodiments, theserver B 250 may be configured to implement some, or all, of thefunctionalities of the computing system 102 as described above. Thedatastore B 252 may include one or more databases (e.g., storingdocument information, such as state information, stateless information,operation logs). The datastore B 252 may include a local replica of thedocument A (e.g., a document replica A′ 254) and a primary replica ofthe document B (e.g., a document replica B 256). The document replica A′254 may be linked to the document replica A 214. The document replica A′254 may include one or more fields that identify or reference thedocument replica A 214. The document replica A′ 254 may include asnapshot of the document replica A 214.

The server A 210 may have ultimate editorial control over the documentA. The server A 210 may exercise ultimate editorial control over thedocument A based on control over the content of the document replica A214. The server B 250 may have ultimate editorial control over thedocument B. The server B 250 may exercise ultimate editorial controlover the document B based on control over the content of the documentreplica B 256.

The server A 210 may receive one or more requests for documents from theclient A 220. Based on a request for document A, the server A 210 mayprovide to the client A 220 the document replica A 214. Based on arequest for document B, the server A 210 may determine the documentreplica B′ 216 (the local replica of the document B in the datastore A212) and subscribe to the document replica B 256 (the primary replica ofthe document B in the datastore B 252) through the server B 250 (remoteserver). The subscription to the document replica B 256 may create aserver-client (e.g., master-slave) relationship between the server B 250and the server A 210 and/or between the document replica B 256 and thedocument replica B′ 216. The server A 210 may provide to the client A220 access to the document B based at least in part on the subscriptionto the document replica B 256.

The server B 250 may receive one or more requests for documents from theclient B 260. Based on a request for document A, the server B 250 maydetermine the document replica A′ 254 (the local replica of the documentA in the datastore B 252) and subscribe to the document replica A 214(the primary replica of the document A in the datastore A 212) throughthe server A 210 (remote server). The subscription to the documentreplica A 214 may create a server-client (e.g., master-slave)relationship between the server A 210 and the server B 250 and/orbetween the document replica A 214 and the document replica A′ 254. Theserver B 250 may provide to the client B 260 access to the document Abased at least in part on the subscription to the document replica A214. Based on a request for document B, the server B 250 may provide tothe client B 260 the document replica B 256.

FIG. 3 illustrates an example diagram 300, in accordance with variousembodiments. The example diagram 300 may include a server A 310, aserver B 350, and a client 360. The server A 310, the server B 350, andthe client 360 may include one or more processors and memory. Theprocessor(s) may be configured to perform various operations byinterpreting machine-readable instructions stored in the memory. Theclient 360 may include a computing device (e.g., desktop device, laptop,mobile device). The client 360 may communicate with the server B 350(e.g., the client 360 is logged into the server B 350).

The server A 310 may include a datastore A 312. In some embodiments, theserver A 310 may be configured to implement some, or all, of thefunctionalities of the computing system 102 and/or the server A 210 asdescribed above. The datastore A 312 may include one or more databases(e.g., storing document information, such as state information,stateless information, operation logs). The datastore A 312 may includea primary replica of a document A (a document replica A 314) and aprimary replica of a document B (a document replica B 316).

The server B 350 may include a datastore B 352. In some embodiments, theserver B 350 may be configured to implement some, or all, of thefunctionalities of the computing system 102 and/or the server B 250 asdescribed above. The datastore B 352 may include one or more databases(e.g., storing document information, such as state information,stateless information, operation logs). The datastore B 352 may includea local replica of the document A (a document replica A′ 354) and alocal replica of the document B (a document replica B′ 356). Thedocument replica A′ 354 may be linked to the document replica A 314. Thedocument replica A′ 354 may include one or more fields that identify orreference the document replica A 314. The document replica A′ 354 mayinclude a snapshot of the document replica A 314. The document replicaB′ 356 may be linked to the document replica B 316. The document replicaB′ 356 may include one or more fields that identify or reference thedocument replica B 316. The document replica B′ 356 may include asnapshot of the document replica B 316.

The server A 310 may have ultimate editorial control over the document Aand the document B. The server A 310 may exercise ultimate editorialcontrol over the document A based on control over the content of thedocument replica A 314. The server A 310 may exercise ultimate editorialcontrol over the document B based on control over the content of thedocument replica B 316.

The server B 350 may receive one or more requests for documents from theclient 360. Based on a request for document A, the server B 350 maydetermine the document replica A′ 354 (the local replica of the documentA in the datastore B 352) and subscribe to the document replica A 314(the primary replica of the document A in the datastore A 312) throughthe server A 310 (remote server). The server B 350 may provide to theclient 360 access to the document A based at least in part on thesubscription to the document replica A 314. Based on a request fordocument B, the server B 350 may determine the document replica B′ 356(the local replica of the document B in the datastore B 352) andsubscribe to the document replica B 316 (the primary replica of thedocument B in the datastore A 312) through the server A 310 (remoteserver). The server B 350 may provide to the client 360 access to thedocument B based at least in part on the subscription to the documentreplica B 316.

The content of the document replica A 314 may be defined at least inpart based on state information, such as operations A 315 (e.g., asrecorded within an operation log for the document replica A 314). Thecontent of the document replica A′ 354 may be defined at least in partbased on state information, such as operations A′ 355 (e.g., as recordedwithin an operation log for the document replica A′ 354). In someembodiments, the operations A′ 355 may be synchronized with theoperations A 315 based on the subscription to the document replica A 314by the server B 350. For example, the operations A 315 may include threenew operations/transactions (e.g., three operations/transactions wereadded to the operations A 315 since the operations A 315 and theoperations A′ 355 were synchronized), which may be copied to theoperations A′ 355. The updated operations A′ 355 may be used by theserver B 350 to provide to the client 360 access to the document A.

The content of the document replica B 316 may be defined at least inpart based on state information, such as operations B 317 (e.g., asrecorded within an operation log), for the document replica B 316. Thecontent of the document replica B′ 356 may be defined at least in partbased on state information, such as operations B′ 357 (e.g., as recordedwithin an operation log), for the document replica B′ 356. In someembodiments, the operations B′ 357 may be synchronized with theoperations B 317 based on the subscription to the document replica B 316by the server B 350. For example, the operations B 317 may include oneless operation/transaction (e.g., an operation/transaction was removedfrom the operations B 317 or an unauthorized change was made to theoperations B′ 357 since the operations B 317 and the operations B′ 357were synchronized), and the additional operation/transaction may beremoved from the operations B′ 357. As another example, the additionaloperation/transaction in the operations B′ 357 may have been authorizedand the operations B 317 may be updated to include the additionaloperation/transaction. The updated operations B′ 357 may be used by theserver B 350 to provide to the client 360 access to the document B. Manyvariations are possible.

FIG. 4 illustrates an example diagram 400, in accordance with variousembodiments. The example diagram 400 may include a server A 410, aclient A 420, a server B 450, and a client B 460. The server A 410, theclient A 420, the server B 450, and the client B 460 may include one ormore processors and memory. The processor(s) may be configured toperform various operations by interpreting machine-readable instructionsstored in the memory. The client A 420 and/or the client B 460 mayinclude a computing device (e.g., desktop device, laptop, mobiledevice). The client A 420 may communicate with the server A 410 (theclient A 420 is logged into the server A 410) and the client B 460 maycommunicate with the server B 450 (the client B 460 is logged into theserver B 450).

The server A 410 may include a datastore A 412. In some embodiments, theserver A 410 may be configured to implement some, or all, of thefunctionalities of the computing system 102, the server A 210, and/orthe server A 310 as described above. The datastore A 412 may include aprimary replica of a document A (a document replica A 414) and a localreplica of a document B (a document replica B′ 416). The server B 450may include a datastore B 452. In some embodiments, the server B 450 maybe configured to implement some, or all, of the functionalities of thecomputing system 102, the server B 250, and/or the server B 350 asdescribed above. The datastore B 452 may include a local replica of thedocument A (a document replica A′ 454) and a primary replica of thedocument B (a document replica B 256).

Based on a request from the client A 420 for the document B 456, theserver A 410 may determine the document replica B′ 416 (the localreplica of the document B 456 in the datastore A 412) and subscribe tothe document replica B 456 (the primary replica of the document B in thedatastore B 452) through the server B 450 (remote server). Based on arequest from the client B 460 for the document A 414, the server B 450may determine the document replica A′ 454 (the local replica of thedocument A 414 in the datastore B 452) and subscribe to the documentreplica A 414 (the primary replica of the document A in the datastore A412) through the server A 410 (remote server).

The client A 420 may be logged into the server A 410 using a givencredential (e.g., token), and access to the document replica B 456 (theprimary replica of the document B in the datastore B 452) by server A410 and through the server B 450 (remote server) may be validated usingthe given credential. The given credential may be validated based ontrust relationships between an exchanger A 435 and authenticationprocesses 430, 470 (e.g., authentication servers). The exchanger A 435may allow sharing of authentication/authorization between differentauthentication processes 430, 470. Such validation of the client A 420may allow a user of the client A 420 to access the document replica B456 by going through an authentication/authorization process for theserver A 410 and without having to go through a separateauthentication/authorization process for the server B 450.

The client B 460 may be logged into the server B 450 using a givencredential (e.g., token), and access to the document replica A 414 (theprimary replica of the document A in the datastore A 412) by the serverB 450 and through the server A 410 (remote server) may be validatedusing the given credential. The given credential may be validated basedon trust relationships between an exchanger B 475 and authenticationprocesses 430, 470 (e.g., authentication servers). The exchanger B 475may allow sharing of authentication/authorization between differentauthentication processes 430, 470. Such validation of the client B 460may allow a user of the client B 460 to access the document replica A414 by going through an authentication/authorization process for theserver B 450 and without having to go through a separateauthentication/authorization process for the server A 410.

In some implementations, the authentication processes 430, 470 maycommunicate with another service (e.g., third-party authenticationservice) which may perform the authentication/authorization. Forexample, both the authentication process A 430 and the authenticationprocess B 470 may use the same authentication/authorization server tovalidate a user's login to the servers 410, 450. The user's loginprocess may result in generation of a credential for the user, which maybe effective for a limited period of time or for an indefinite period oftime. Cryptographically secure trust relationships may be establishedbetween the authentication processes 430, 470 (via the exchanger A 435,the exchanger B 475) to allow credentials to be exchanged. There may betrusted pairwise relationships between an exchanger and individualauthentication processes to which the exchanger is authorized toauthenticate credentials. For example, trusted pairwise relationshipsmay exist between the exchanger A 435 and the authentication process A430, the exchanger A 435 and the authentication process B 470, theexchanger B 475 and the authentication process A 430, and the exchangerB 475 and the authentication process B 470.

For example, the client A 420 may have logged into the server A 410 viathe authentication process A 430, which may have resulted in generationof a credential for the client A 420 by the authentication process A430. Based on a request for document B by the client A 420, the server A410 may seek to subscribe to the document replica B 456 accessiblethrough the server B 450. The server A 410 may provide the credentialfor the client A 420 to the server B 450. The server B 450 may query theauthentication process B 470 to determine whether the receivedcredential is valid (i.e., check whether the client A 420 is authorizedto access the server B 450). The authentication process B 470 may notrecognize this credential because it was not used in the login processinvolving the client A 420 and the server A 410. The authenticationprocess B 470 may query the exchanger B 475 to determine whether thecredential is valid. The exchanger B 475 may in turn query theauthentication process A 430 (e.g., source authentication server) todetermine whether the received credential is valid (i.e., check whetherthe client A 420 has valid access to the server A 410). Based on thecredential being validated by the authentication process A 430, accessof the credential may be validated for access of the server B 450.

In some embodiments, the authentication process B 470 may generate ashell credential for use based on receiving a credential generated byanother authentication process. This may result in exchanging acredential from another authentication process with an internalcredential. The shell credential may use the original credential expirydate so that they expire at the same time.

FIG. 5 illustrates an example diagram 500, in accordance with variousembodiments. The example diagram 500 may include a server A 510, aserver B 550, an authentication process A 530, an authenticationprocessor B 570, an exchanger A 535, and an exchanger B 575. The serverA 510 and the server B 550 may include one or more processors andmemory. The processor(s) may be configured to perform various operationsby interpreting machine-readable instructions stored in the memory. Theserver A 510 may include a datastore A 512. In some embodiments, theserver A 510 may be configured to implement some, or all, of thefunctionalities of the computing system 102, the server A 210, theserver A 310, and/or the server A 410 as described above. The datastoreA 512 may include a primary replica of a document A (a document replicaA 514) and a primary replica of a document B (a document replica B 516).The server B 550 may include a datastore B 552. In some embodiments, theserver B 550 may be configured to implement some, or all, of thefunctionalities of the computing system 102, the server B 250, theserver B 350, and/or the server B 450 as described above. The datastoreB 552 may include a local replica of a document A (a document replica A′554) and a local replica of a document B (a document replica B′ 556).

The content of the document replica A 514 may be defined at least inpart based on state information, such as operations A 515 (e.g., asrecorded within an operation log for the document replica A 514). Thecontent of the document replica A′ 554 may be defined at least in partbased on state information, such as operations A′ 555 (e.g., as recordedwithin an operation log for the document replica A′ 554). The content ofthe document replica B 516 may be defined based at least in part onstate information, such as operations B 517 (e.g., as recorded within anoperation log for the document replica B 516). The content of thedocument replica B′ 556 may be defined based at least in part on stateinformation, such as operations B′ 557 (e.g., as recorded within anoperation log for the document replica B′ 556).

A client may log into the server A 510 through the authenticationprocess A 530 (e.g., an authentication server). In some embodiments, theauthentication process A 530 may be configured to implement some, orall, of the functionalities of the authentication process A 430 asdescribed above. A trust relationship may exist between the exchanger A535 and the authentication process A 530. A trust relationship may existbetween the exchanger A 535 and the authentication process B 570. Insome embodiments, the exchanger A 535 may be configured to implementsome, or all, of the functionalities of the exchanger A 435 as describedabove. Trusted pairwise relationships may exist between the exchanger A535 and the authentication process A 530, the exchanger A 535 and theauthentication process B 570, the exchanger B 575 and the authenticationprocess A 530, and the exchanger B 575 and the authentication process B570.

A client may log into the server B 550 through the authenticationprocess B 570 (e.g., an authentication server). In some embodiments, theauthentication process B 570 may be configured to implement some, orall, of the functionalities of the authentication process B 470 asdescribed above. A trust relationship may exist between the exchanger B575 and the authentication process A 530. A trust relationship may existbetween the exchanger B 575 and the authentication process B 570. Insome embodiments, the exchanger B 575 may be configured to implementsome, or all, of the functionalities of the exchanger B 475 as describedabove.

One or more clients may be logged into the server A 510. Access by theclient(s) of the server A 510 of the document A may include a view A 520of the document replica A 514. Access by the client(s) of the server A510 of the document B may include a view B 525 of the document replica B516.

One or more clients may be logged into the server B 550. Access by theclient(s) of the server B 550 to the document A may include a view A′560 of the document replica A 514 based on the linking between thedocument replica A 514 and the document replica A′ 554. Based on thelinking between the document replica A 514 and the document replica A′554, the server B 550 may subscribe to the document replica A 514through the server A 510 and can provide the view A′ 560 to itsclient(s) based at least in part on the subscription to the documentreplica A 514. Access by the client(s) of the server B 550 of thedocument B may include a view B′ 565 of the document replica B 516 basedon the linking between the document replica B 516 and the documentreplica B′ 556. Based on the linking between the document replica B 516and the document replica B′ 556, the server B 550 may subscribe to thedocument replica B 516 through the server A 510 and can provide the viewB′ 565 to its client(s) based at least in part on the subscription tothe document replica B 516. Many variations are possible.

FIG. 6 illustrates a flowchart of an example method 600, according tovarious embodiments of the present disclosure. The method 600 may beimplemented in various environments including, for example, theenvironment 100 of FIG. 1 . The operations of method 600 presented beloware intended to be illustrative. Depending on the implementation, theexample method 600 may include additional, fewer, or alternative stepsperformed in various orders or in parallel. The example method 500 maybe implemented in various computing systems or devices including one ormore processors.

At block 602, a request for a document may be received from a computingdevice. Content of the document may be defined based on stateinformation and stateless information. At block 604, a local replica ofthe document may be determined in a local database. The local replica ofthe document may be linked to a primary replica of the document andinclude a snapshot of the primary replica of the document. The primaryreplica of the document may be stored in a remote database that isaccessible through a remote server. At block 606, the primary replica ofthe document may be subscribed to through the remote server. At block608, access to the document may be provided to the computing devicebased at least in part of the subscription to the primary replica of thedocument.

Hardware Implementation

The techniques described herein are implemented by one or morespecial-purpose computing devices. The special-purpose computing devicesmay be hard-wired to perform the techniques, or may include circuitry ordigital electronic devices such as one or more application-specificintegrated circuits (ASICs) or field programmable gate arrays (FPGAs)that are persistently programmed to perform the techniques, or mayinclude one or more hardware processors programmed to perform thetechniques pursuant to program instructions in firmware, memory, otherstorage, or a combination. Such special-purpose computing devices mayalso combine custom hard-wired logic, ASICs, or FPGAs with customprogramming to accomplish the techniques. The special-purpose computingdevices may be desktop computer systems, server computer systems,portable computer systems, handheld devices, networking devices or anyother device or combination of devices that incorporate hard-wiredand/or program logic to implement the techniques.

Computing device(s) are generally controlled and coordinated byoperating system software, such as iOS, Android, Chrome OS, Windows XP,Windows Vista, Windows 7, Windows 8, Windows Server, Windows CE, Unix,Linux, SunOS, Solaris, iOS, Blackberry OS, VxWorks, or other compatibleoperating systems. In other embodiments, the computing device may becontrolled by a proprietary operating system. Conventional operatingsystems control and schedule computer processes for execution, performmemory management, provide file system, networking, I/O services, andprovide a user interface functionality, such as a graphical userinterface (“GUI”), among other things.

FIG. 7 is a block diagram that illustrates a computer system 700 uponwhich any of the embodiments described herein may be implemented. Thecomputer system 700 includes a bus 702 or other communication mechanismfor communicating information, one or more hardware processors 704coupled with bus 702 for processing information. Hardware processor(s)704 may be, for example, one or more general purpose microprocessors.

The computer system 700 also includes a main memory 706, such as arandom access memory (RAM), cache and/or other dynamic storage devices,coupled to bus 702 for storing information and instructions to beexecuted by processor 704. Main memory 706 also may be used for storingtemporary variables or other intermediate information during executionof instructions to be executed by processor 704. Such instructions, whenstored in storage media accessible to processor 704, render computersystem 700 into a special-purpose machine that is customized to performthe operations specified in the instructions.

The computer system 700 further includes a read only memory (ROM) 708 orother static storage device coupled to bus 702 for storing staticinformation and instructions for processor 704. A storage device 710,such as a magnetic disk, optical disk, or USB thumb drive (Flash drive),etc., is provided and coupled to bus 702 for storing information andinstructions.

The computer system 700 may be coupled via bus 702 to a display 712,such as a cathode ray tube (CRT) or LCD display (or touch screen), fordisplaying information to a computer user. An input device 714,including alphanumeric and other keys, is coupled to bus 702 forcommunicating information and command selections to processor 704.Another type of user input device is cursor control 716, such as amouse, a trackball, or cursor direction keys for communicating directioninformation and command selections to processor 704 and for controllingcursor movement on display 712. This input device typically has twodegrees of freedom in two axes, a first axis (e.g., x) and a second axis(e.g., y), that allows the device to specify positions in a plane. Insome embodiments, the same direction information and command selectionsas cursor control may be implemented via receiving touches on a touchscreen without a cursor.

The computing system 700 may include a user interface module toimplement a GUI that may be stored in a mass storage device asexecutable software codes that are executed by the computing device(s).This and other modules may include, by way of example, components, suchas software components, object-oriented software components, classcomponents and task components, processes, functions, attributes,procedures, subroutines, segments of program code, drivers, firmware,microcode, circuitry, data, databases, data structures, tables, arrays,and variables.

In general, the word “module,” as used herein, refers to logic embodiedin hardware or firmware, or to a collection of software instructions,possibly having entry and exit points, written in a programminglanguage, such as, for example, Java, C or C++. A software module may becompiled and linked into an executable program, installed in a dynamiclink library, or may be written in an interpreted programming languagesuch as, for example, BASIC, Perl, or Python. It will be appreciatedthat software modules may be callable from other modules or fromthemselves, and/or may be invoked in response to detected events orinterrupts. Software modules configured for execution on computingdevices may be provided on a computer readable medium, such as a compactdisc, digital video disc, flash drive, magnetic disc, or any othertangible medium, or as a digital download (and may be originally storedin a compressed or installable format that requires installation,decompression or decryption prior to execution). Such software code maybe stored, partially or fully, on a memory device of the executingcomputing device, for execution by the computing device. Softwareinstructions may be embedded in firmware, such as an EPROM. It will befurther appreciated that hardware modules may be comprised of connectedlogic units, such as gates and flip-flops, and/or may be comprised ofprogrammable units, such as programmable gate arrays or processors. Themodules or computing device functionality described herein arepreferably implemented as software modules, but may be represented inhardware or firmware. Generally, the modules described herein refer tological modules that may be combined with other modules or divided intosub-modules despite their physical organization or storage.

The computer system 700 may implement the techniques described hereinusing customized hard-wired logic, one or more ASICs or FPGAs, firmwareand/or program logic which in combination with the computer systemcauses or programs computer system 700 to be a special-purpose machine.According to one embodiment, the techniques herein are performed bycomputer system 700 in response to processor(s) 704 executing one ormore sequences of one or more instructions contained in main memory 706.Such instructions may be read into main memory 706 from another storagemedium, such as storage device 710. Execution of the sequences ofinstructions contained in main memory 706 causes processor(s) 704 toperform the process steps described herein. In alternative embodiments,hard-wired circuitry may be used in place of or in combination withsoftware instructions.

The term “non-transitory media,” and similar terms, as used hereinrefers to any media that store data and/or instructions that cause amachine to operate in a specific fashion. Such non-transitory media maycomprise non-volatile media and/or volatile media. Non-volatile mediaincludes, for example, optical or magnetic disks, such as storage device710. Volatile media includes dynamic memory, such as main memory 706.Common forms of non-transitory media include, for example, a floppydisk, a flexible disk, hard disk, solid state drive, magnetic tape, orany other magnetic data storage medium, a CD-ROM, any other optical datastorage medium, any physical medium with patterns of holes, a RAM, aPROM, and EPROM, a FLASH-EPROM, NVRAM, any other memory chip orcartridge, and networked versions of the same.

Non-transitory media is distinct from but may be used in conjunctionwith transmission media. Transmission media participates in transferringinformation between non-transitory media. For example, transmissionmedia includes coaxial cables, copper wire and fiber optics, includingthe wires that comprise bus 702. Transmission media can also take theform of acoustic or light waves, such as those generated duringradio-wave and infra-red data communications.

Various forms of media may be involved in carrying one or more sequencesof one or more instructions to processor 704 for execution. For example,the instructions may initially be carried on a magnetic disk or solidstate drive of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 700 canreceive the data on the telephone line and use an infra-red transmitterto convert the data to an infra-red signal. An infra-red detector canreceive the data carried in the infra-red signal and appropriatecircuitry can place the data on bus 702. Bus 702 carries the data tomain memory 706, from which processor 704 retrieves and executes theinstructions. The instructions received by main memory 706 mayoptionally be stored on storage device 710 either before or afterexecution by processor 704.

The computer system 700 also includes a communication interface 718coupled to bus 702. Communication interface 718 provides a two-way datacommunication coupling to one or more network links that are connectedto one or more local networks. For example, communication interface 718may be an integrated services digital network (ISDN) card, cable modem,satellite modem, or a modem to provide a data communication connectionto a corresponding type of telephone line. As another example,communication interface 718 may be a local area network (LAN) card toprovide a data communication connection to a compatible LAN (or WANcomponent to communicated with a WAN). Wireless links may also beimplemented. In any such implementation, communication interface 718sends and receives electrical, electromagnetic or optical signals thatcarry digital data streams representing various types of information.

A network link typically provides data communication through one or morenetworks to other data devices. For example, a network link may providea connection through local network to a host computer or to dataequipment operated by an Internet Service Provider (ISP). The ISP inturn provides data communication services through the world wide packetdata communication network now commonly referred to as the “Internet”.Local network and Internet both use electrical, electromagnetic oroptical signals that carry digital data streams. The signals through thevarious networks and the signals on network link and throughcommunication interface 718, which carry the digital data to and fromcomputer system 700, are example forms of transmission media.

The computer system 700 can send messages and receive data, includingprogram code, through the network(s), network link and communicationinterface 718. In the Internet example, a server might transmit arequested code for an application program through the Internet, the ISP,the local network and the communication interface 718.

The received code may be executed by processor 704 as it is received,and/or stored in storage device 710, or other non-volatile storage forlater execution.

Each of the processes, methods, and algorithms described in thepreceding sections may be embodied in, and fully or partially automatedby, code modules executed by one or more computer systems or computerprocessors comprising computer hardware. The processes and algorithmsmay be implemented partially or wholly in application-specificcircuitry.

The various features and processes described above may be usedindependently of one another, or may be combined in various ways. Allpossible combinations and sub-combinations are intended to fall withinthe scope of this disclosure. In addition, certain method or processblocks may be omitted in some implementations. The methods and processesdescribed herein are also not limited to any particular sequence, andthe blocks or states relating thereto can be performed in othersequences that are appropriate. For example, described blocks or statesmay be performed in an order other than that specifically disclosed, ormultiple blocks or states may be combined in a single block or state.The example blocks or states may be performed in serial, in parallel, orin some other manner. Blocks or states may be added to or removed fromthe disclosed example embodiments. The example systems and componentsdescribed herein may be configured differently than described. Forexample, elements may be added to, removed from, or rearranged comparedto the disclosed example embodiments.

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Any process descriptions, elements, or blocks in the flow diagramsdescribed herein and/or depicted in the attached figures should beunderstood as potentially representing modules, segments, or portions ofcode which include one or more executable instructions for implementingspecific logical functions or steps in the process. Alternateimplementations are included within the scope of the embodimentsdescribed herein in which elements or functions may be deleted, executedout of order from that shown or discussed, including substantiallyconcurrently or in reverse order, depending on the functionalityinvolved, as would be understood by those skilled in the art.

It should be emphasized that many variations and modifications may bemade to the above-described embodiments, the elements of which are to beunderstood as being among other acceptable examples. All suchmodifications and variations are intended to be included herein withinthe scope of this disclosure. The foregoing description details certainembodiments of the invention. It will be appreciated, however, that nomatter how detailed the foregoing appears in text, the invention can bepracticed in many ways. As is also stated above, it should be noted thatthe use of particular terminology when describing certain features oraspects of the invention should not be taken to imply that theterminology is being re-defined herein to be restricted to including anyspecific characteristics of the features or aspects of the inventionwith which that terminology is associated. The scope of the inventionshould therefore be construed in accordance with the appended claims andany equivalents thereof.

Engines, Components, and Logic

Certain embodiments are described herein as including logic or a numberof components, engines, or mechanisms. Engines may constitute eithersoftware engines (e.g., code embodied on a machine-readable medium) orhardware engines. A “hardware engine” is a tangible unit capable ofperforming certain operations and may be configured or arranged in acertain physical manner. In various example embodiments, one or morecomputer systems (e.g., a standalone computer system, a client computersystem, or a server computer system) or one or more hardware engines ofa computer system (e.g., a processor or a group of processors) may beconfigured by software (e.g., an application or application portion) asa hardware engine that operates to perform certain operations asdescribed herein.

In some embodiments, a hardware engine may be implemented mechanically,electronically, or any suitable combination thereof. For example, ahardware engine may include dedicated circuitry or logic that ispermanently configured to perform certain operations. For example, ahardware engine may be a special-purpose processor, such as aField-Programmable Gate Array (FPGA) or an Application SpecificIntegrated Circuit (ASIC). A hardware engine may also includeprogrammable logic or circuitry that is temporarily configured bysoftware to perform certain operations. For example, a hardware enginemay include software executed by a general-purpose processor or otherprogrammable processor. Once configured by such software, hardwareengines become specific machines (or specific components of a machine)uniquely tailored to perform the configured functions and are no longergeneral-purpose processors. It will be appreciated that the decision toimplement a hardware engine mechanically, in dedicated and permanentlyconfigured circuitry, or in temporarily configured circuitry (e.g.,configured by software) may be driven by cost and time considerations.

Accordingly, the phrase “hardware engine” should be understood toencompass a tangible entity, be that an entity that is physicallyconstructed, permanently configured (e.g., hardwired), or temporarilyconfigured (e.g., programmed) to operate in a certain manner or toperform certain operations described herein. As used herein,“hardware-implemented engine” refers to a hardware engine. Consideringembodiments in which hardware engines are temporarily configured (e.g.,programmed), each of the hardware engines need not be configured orinstantiated at any one instance in time. For example, where a hardwareengine comprises a general-purpose processor configured by software tobecome a special-purpose processor, the general-purpose processor may beconfigured as respectively different special-purpose processors (e.g.,comprising different hardware engines) at different times. Softwareaccordingly configures a particular processor or processors, forexample, to constitute a particular hardware engine at one instance oftime and to constitute a different hardware engine at a differentinstance of time.

Hardware engines can provide information to, and receive informationfrom, other hardware engines. Accordingly, the described hardwareengines may be regarded as being communicatively coupled. Where multiplehardware engines exist contemporaneously, communications may be achievedthrough signal transmission (e.g., over appropriate circuits and buses)between or among two or more of the hardware engines. In embodiments inwhich multiple hardware engines are configured or instantiated atdifferent times, communications between such hardware engines may beachieved, for example, through the storage and retrieval of informationin memory structures to which the multiple hardware engines have access.For example, one hardware engine may perform an operation and store theoutput of that operation in a memory device to which it iscommunicatively coupled. A further hardware engine may then, at a latertime, access the memory device to retrieve and process the storedoutput. Hardware engines may also initiate communications with input oroutput devices, and can operate on a resource (e.g., a collection ofinformation).

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implemented enginesthat operate to perform one or more operations or functions describedherein. As used herein, “processor-implemented engine” refers to ahardware engine implemented using one or more processors.

Similarly, the methods described herein may be at least partiallyprocessor-implemented, with a particular processor or processors beingan example of hardware. For example, at least some of the operations ofa method may be performed by one or more processors orprocessor-implemented engines. Moreover, the one or more processors mayalso operate to support performance of the relevant operations in a“cloud computing” environment or as a “software as a service” (SaaS).For example, at least some of the operations may be performed by a groupof computers (as examples of machines including processors), with theseoperations being accessible via a network (e.g., the Internet) and viaone or more appropriate interfaces (e.g., an Application ProgramInterface (API)).

The performance of certain of the operations may be distributed amongthe processors, not only residing within a single machine, but deployedacross a number of machines. In some example embodiments, the processorsor processor-implemented engines may be located in a single geographiclocation (e.g., within a home environment, an office environment, or aserver farm). In other example embodiments, the processors orprocessor-implemented engines may be distributed across a number ofgeographic locations.

Language

Throughout this specification, plural instances may implementcomponents, operations, or structures described as a single instance.Although individual operations of one or more methods are illustratedand described as separate operations, one or more of the individualoperations may be performed concurrently, and nothing requires that theoperations be performed in the order illustrated. Structures andfunctionality presented as separate components in example configurationsmay be implemented as a combined structure or component. Similarly,structures and functionality presented as a single component may beimplemented as separate components. These and other variations,modifications, additions, and improvements fall within the scope of thesubject matter herein.

Although an overview of the subject matter has been described withreference to specific example embodiments, various modifications andchanges may be made to these embodiments without departing from thebroader scope of embodiments of the present disclosure. Such embodimentsof the subject matter may be referred to herein, individually orcollectively, by the term “invention” merely for convenience and withoutintending to voluntarily limit the scope of this application to anysingle disclosure or concept if more than one is, in fact, disclosed.

The embodiments illustrated herein are described in sufficient detail toenable those skilled in the art to practice the teachings disclosed.Other embodiments may be used and derived therefrom, such thatstructural and logical substitutions and changes may be made withoutdeparting from the scope of this disclosure. The Detailed Description,therefore, is not to be taken in a limiting sense, and the scope ofvarious embodiments is defined only by the appended claims, along withthe full range of equivalents to which such claims are entitled.

It will be appreciated that an “engine,” “system,” “data store,” and/or“database” may comprise software, hardware, firmware, and/or circuitry.In one example, one or more software programs comprising instructionscapable of being executable by a processor may perform one or more ofthe functions of the engines, data stores, databases, or systemsdescribed herein. In another example, circuitry may perform the same orsimilar functions. Alternative embodiments may comprise more, less, orfunctionally equivalent engines, systems, data stores, or databases, andstill be within the scope of present embodiments. For example, thefunctionality of the various systems, engines, data stores, and/ordatabases may be combined or divided differently.

“Open source” software is defined herein to be source code that allowsdistribution as source code as well as compiled form, with awell-publicized and indexed means of obtaining the source, optionallywith a license that allows modifications and derived works.

The data stores described herein may be any suitable structure (e.g., anactive database, a relational database, a self-referential database, atable, a matrix, an array, a flat file, a documented-oriented storagesystem, a non-relational No-SQL system, and the like), and may becloud-based or otherwise.

As used herein, the term “or” may be construed in either an inclusive orexclusive sense. Moreover, plural instances may be provided forresources, operations, or structures described herein as a singleinstance. Additionally, boundaries between various resources,operations, engines, engines, and data stores are somewhat arbitrary,and particular operations are illustrated in a context of specificillustrative configurations. Other allocations of functionality areenvisioned and may fall within a scope of various embodiments of thepresent disclosure. In general, structures and functionality presentedas separate resources in the example configurations may be implementedas a combined structure or resource. Similarly, structures andfunctionality presented as a single resource may be implemented asseparate resources. These and other variations, modifications,additions, and improvements fall within a scope of embodiments of thepresent disclosure as represented by the appended claims. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense.

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred implementations, it is to be understood thatsuch detail is solely for that purpose and that the invention is notlimited to the disclosed implementations, but, on the contrary, isintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the appended claims. For example, it isto be understood that the present invention contemplates that, to theextent possible, one or more features of any embodiment can be combinedwith one or more features of any other embodiment.

The invention claimed is:
 1. A system comprising: one or moreprocessors; and a memory storing instructions that, when executed by theone or more processors, cause the system to perform: receiving anindication of a first update to a first replica of a document from afirst computing device, wherein the document comprises state andstateless information and the first replica is a snapshot of thedocument, the state information changing with respect to time or versionand the stateless information being unchanging with respect to time orversion, wherein the first update is recorded in a first operation logassociated with the first replica; determining whether the first updateis confirmed; and based on whether the first update is confirmed,selectively: implementing the first update; recording the first updatein a second operation log associated with the system; performing one ormore operations on top of the snapshot or another snapshot of thedocument to arrive at a consistent state; and propagating the firstupdate from the system to one or more second replicas associated withone or more respective second computing devices.
 2. The system of claim1, wherein the state information comprises one or more editable objectsassociated with the document.
 3. The system of claim 1, wherein thestateless information comprises at least one of an image, video, oraudio associated with the document.
 4. The system of claim 1, whereinthe stateless information is locally stored.
 5. The system of claim 1,wherein the system is associated with a third replica of the document,the third replica comprising a primary replica, and the instructionsfurther cause the system to perform: receiving an edit to the documentfrom the first computing device; and transmitting information describingthe edit to the system, the system having editorial control over thethird replica of the document.
 6. The system of claim 1, wherein thefirst computing device is logged into the system using a credential, andthe system access to the third replica of the document through thesystem is validated using the credential.
 7. The system of claim 1,wherein the credential is validated based on trust relationships betweenan exchanger and authentication processes.
 8. The system of claim 7,wherein the stateless information corresponds to content of the documentthat does not change with the updates to the first operation log or thesecond operation log.
 9. The system of claim 1, wherein the documentincludes a map, and wherein the stateless information corresponds tomedia content items associated with one or more locations on the map andstate information corresponds to annotations associated with the one ormore locations.
 10. The system of claim 9, wherein the media contentitems include at least one of images, video, or audio associated withthe one or more locations and the annotations include at least one routeoverlaid over the one or more locations.
 11. The system of claim 1,wherein the system is associated with a primary replica of the document,the instructions further cause the system to perform: switching theprimary replica from the system to a second computing device, whereinthe second computing device determines whether to confirm any updates tothe document from a different replica; receiving an indication that thesecond computing device confirms a second update to the document; andimplementing the second update to the document at the system.
 12. Acomputer-implemented method comprising: receiving, by a computingsystem, an indication of a first update to a first replica of a documentfrom a first computing device, wherein the document comprises state andstateless information and the first replica is a snapshot of thedocument, the state information changing with respect to time or versionand the stateless information being unchanging with respect to time orversion, wherein the first update is recorded in a first operation logassociated with the first replica; determining, by the computing system,whether the first update is confirmed; and based on whether the firstupdate is confirmed, selectively: implementing the first update;recording the first update in a second operation log associated with thecomputing system; performing one or more operations on top of thesnapshot or another snapshot of the document to arrive at a consistentstate; and propagating the first update from the computing system to oneor more second replicas associated with one or more respective secondcomputing devices.
 13. The computer-implemented method of claim 12,wherein the state information comprises one or more editable objectsassociated with the document.
 14. The computer-implemented method ofclaim 12, wherein the stateless information comprises at least one of animage, video, or audio associated with the document.
 15. Thecomputer-implemented method of claim 12, wherein the first replica isstored at the first computing device and the computing system isassociated with a primary replica.
 16. The computer-implemented methodof claim 12, wherein the first update is initiated by the firstcomputing device upon launching of the first replica at the firstcomputing device.
 17. A non-transitory computer-readable medium storinginstructions that, when executed by one or more processors of acomputing system, cause the computing system to perform a methodcomprising: receiving an indication of a first update to a first replicaof a document from a first computing device, wherein the documentcomprises state and stateless information and the first replica is asnapshot of the document, the state information changing with respect totime or version and the stateless information being unchanging withrespect to time or version, wherein the first update is recorded in afirst operation log associated with the first replica; determiningwhether the first update is confirmed; and based on whether the firstupdate is confirmed, selectively: implementing the first update;recording the first update in a second operation log associated with thesystem; performing one or more operations on top of a snapshot oranother snapshot of the document to arrive at a consistent state; andpropagating the first update from the system to one or more secondreplicas associated with one or more respective second computingdevices.
 18. The non-transitory computer-readable medium of claim 17,wherein the state information comprises one or more editable objectsassociated with the document.
 19. The non-transitory computer-readablemedium of claim 17, wherein the stateless information comprises at leastone of an image, video, or audio associated with the document.
 20. Thenon-transitory computer-readable medium of claim 17, wherein the firstreplica is stored at the first computing device and the computing systemis associated with a primary replica.